$summon marker ~ ~ ~ {Tags:[util.noriding_kill,temp],data:{byMIS:$(UUID)}}
ride @n[tag=temp,distance=..1,type=marker] mount @n[type=item,nbt={Age:0s},distance=..1,nbt={Item:{components:{"minecraft:custom_data":{byMIS:true}}}}]
tag @n[tag=temp,distance=..1,type=marker] remove temp